Hypervolemic-hemodilution and hypertension during temporary middle cerebral artery occlusion in rats: the effect on blood-brain barrier permeability.
The effect of hypervolemic-hemodilution, with and without hypertension, on blood-brain barrier permeability was investigated in rats, after 180 minutes of middle cerebral artery occlusion (MCAo), and 60 minutes of reperfusion. One of the following conditions was maintained during MCAo: 1) Control--hematocrit and blood pressure were not manipulated; 2) Hypervolemic-Hemodilution/Normotension--the hematocrit was decreased to 30%; 3) Hypervolemic-Hemodilution/Hypertension--the hematocrit was decreased to 30% and mean arterial pressure increased by 30 mmHg with phenylphrine. In all groups, Evans Blue was administered, and its concentration determined by spectrophotometric assay. Evans Blue (micrograms (g-1 of brain tissue [mean +/- SD]) was greater in the Hypervolemic-Hemodilution/Hypertension group (71 +/- 20) versus the Control (13 +/- 9) and Hypervolemic-Hemodilution/Normotension (17 +/- 10) groups (p less than 0.05). No other differences were present. These results support the hypothesis that during MCAo, hypervolemic-hemodilution/hypertensive therapy effects an increase in blood-brain barrier permeability in the early period of reperfusion.
Cole
D J
DJ
Department of Anesthesiology, Loma Linda University, California 92354.
Drummond
J C
JC
Matsumura
J S
JS
Marcantonio
S
S
Chi-Lum
B I
BI
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001812:Blood-Brain Barrier / Q000502:physiology*; D002536:Cerebral Arteries / Q000502:physiology*; D002560:Cerebrovascular Circulation / Q000502:physiology; D005070:Evans Blue; D006400:Hematocrit; D006438:Hemodilution / Q000009:adverse effects*; D006973:Hypertension / Q000503:physiopathology*; D008026:Ligation; D008297:Male; D009994:Osmolar Concentration; D010539:Permeability; D051381:Rats; D011918:Rats, Inbred SHR; D015424:Reperfusion
D001786:Blood Glucose; D005070:Evans Blue